diff --git a/ERROR_CODES.md b/ERROR_CODES.md
new file mode 100644
index 0000000..f336502
--- /dev/null
+++ b/ERROR_CODES.md
@@ -0,0 +1,60 @@
+# GDE GoZen error codes
+
+## Video class
+
+### get_video_file_meta
+
+No error code but returns an empty dictionary when nothing was able to be read.
+
+### open_video
+
+- 0: OK;
+- -1: Couldn't open video file; 
+- -2: Failed setting up of audio decoder;
+- -3: Failed setting up of video decoder;
+- -4: Failed setting up of SWS;
+- -5: Video file is not usable due to limitations;
+- -6: Invalid frame-rate found in video;
+- -7: Could not establish the total amount of frames in video files;
+- -8: Failed setting up of SWR; 
+- -9: Audio seeking error;
+
+### seek_frame and next_frame
+
+No error code but returns an empty picture when an error occured.
+
+## Renderer class
+
+### open
+
+- 0: OK;
+- -1: Renderer not fully ready (some variables aren't set);
+- -2: Failed to open video context;
+- -3: Failed to setup video encoder; 
+- -4: failed to setup audio encoder;
+- -5: Failed to setup video stream;
+- -6: Failed to setup audio stream;
+- -7: Couldn't create packet;
+- -8: Couldn't create frame;
+- -9: Couldn't create SWS;
+- -10: Couldn't create SWR;
+- -11: Failed to open video file;
+- -12: Failed to write stream header;
+
+### send_frame
+
+- 0: OK;
+- -1: Video codec isn't open;
+- -2: Frame is not write-able;
+- -3: Couldn't send frame to encoder; 
+
+Any other response is an FFmpeg error code which has to do with sending, receiving, and writing frames.
+
+
+### send_audio
+
+- 0: OK;
+- -1: Audio rendering is not enabled;
+- -2: Audio codec isn't open;
+
+###
diff --git a/src/renderer.cpp b/src/renderer.cpp
index c53eda5..95f4bc8 100644
--- a/src/renderer.cpp
+++ b/src/renderer.cpp
@@ -1,7 +1,6 @@
 #include "renderer.hpp"
 #include <libavcodec/packet.h>
 
-// TODO: Set proper return errors and document them!
 
 Renderer::~Renderer() {
 	close();
@@ -119,7 +118,7 @@ int Renderer::open() {
 	av_stream_video = avformat_new_stream(av_format_ctx, NULL);
 	if (!av_stream_video) {
 		UtilityFunctions::printerr("Couldn't create stream!");
-		return -3;
+		return -7;
 	}
 
 	av_codec_ctx_video->codec_id = av_codec_id_video;
@@ -137,25 +136,25 @@ int Renderer::open() {
 		av_codec_audio = avcodec_find_encoder(av_codec_id_audio);
 		if (!av_codec_audio) {
 			UtilityFunctions::printerr("Audio codec not found!");
-			return -3;
+			return -4;
 		}
 
 		av_codec_ctx_audio = avcodec_alloc_context3(av_codec_audio);
 		if (!av_codec_ctx_audio) {
 			UtilityFunctions::printerr("Couldn't allocate audio codec context!");
-			return -3;
+			return -4;
 		}
 
 		av_packet_audio = av_packet_alloc();
 		if (!av_packet_audio) {
 			UtilityFunctions::printerr("Couldn't allocate packet!");
-			return -3;
+			return -7;
 		}
 
 		av_stream_audio = avformat_new_stream(av_format_ctx, NULL);
 		if (!av_stream_audio) {
 			UtilityFunctions::printerr("Couldn't create new stream!");
-			return -3;
+			return -6;
 		}
 
 		av_codec_ctx_audio->sample_fmt = (*av_codec_audio).sample_fmts ? (*av_codec_audio).sample_fmts[0] : AV_SAMPLE_FMT_FLTP;
@@ -179,8 +178,8 @@ int Renderer::open() {
 	}
 
 	// TODO: Add options in render profile for these type of things
-	// if (codec->id == AV_CODEC_ID_H264)
-	//   av_opt_set(p_codec_context->priv_data, "preset", "slow", 0);
+	if (av_codec_video->id == AV_CODEC_ID_H264)
+		av_opt_set(p_codec_context->priv_data, "preset", "slow", 0);
 
 	// Opening the video encoder codec
 	response = avcodec_open2(av_codec_ctx_video, av_codec_video, NULL);
@@ -201,19 +200,19 @@ int Renderer::open() {
 	av_packet_video = av_packet_alloc();
 	if (!av_packet_video) {
 		UtilityFunctions::printerr("Couldn't allocate packet!");
-		return -3;
+		return -7;
 	}
 	av_frame_video = av_frame_alloc();
 	if (!av_frame_video) {
 		UtilityFunctions::printerr("Couldn't allocate frame!");
-		return -3;
+		return -8;
 	}
 	av_frame_video->format = AV_PIX_FMT_YUV420P;
 	av_frame_video->width = resolution.x;
 	av_frame_video->height = resolution.y;
 	if (av_frame_get_buffer(av_frame_video, 0)) {
 		UtilityFunctions::printerr("Couldn't allocate frame data!");
-		return -3;
+		return -8;
 	}
 
 	sws_ctx = sws_getContext(
@@ -222,13 +221,13 @@ int Renderer::open() {
 		SWS_BILINEAR, NULL, NULL, NULL); // TODO: Option to change SWS_BILINEAR
 	if (!sws_ctx) {
 		UtilityFunctions::printerr("Couldn't get sws context!");
-		return -7;
+		return -9;
 	}
 
 	// Copy video stream params to muxer
 	if (avcodec_parameters_from_context(av_stream_video->codecpar, av_codec_ctx_video) < 0) {
 		UtilityFunctions::printerr("Couldn't copy video stream params!");
-		return -3;
+		return -5;
 	}
 
 	if (render_audio) {
@@ -260,7 +259,7 @@ int Renderer::open() {
 		swr_ctx = swr_alloc();
 		if (!swr_ctx) {
 			UtilityFunctions::printerr("Couldn't allocate swr!");
-			return -4;
+			return -10;
 		}
 
 		// Setting audio options
@@ -274,7 +273,7 @@ int Renderer::open() {
 		// Initialize resampling context
 		if ((response = swr_init(swr_ctx)) < 0) {
 			UtilityFunctions::printerr("Failed to initialize resampling context!");
-			return -4;
+			return -10;
 		}
 	}
 
@@ -285,7 +284,7 @@ int Renderer::open() {
 		response = avio_open(&av_format_ctx->pb, file_path.utf8(), AVIO_FLAG_WRITE);
 		if (response < 0) {
 			UtilityFunctions::printerr("Couldn't open output file!", get_av_error());
-			return -5;
+			return -11;
 		}
 	}
 
@@ -293,14 +292,13 @@ int Renderer::open() {
 	response = avformat_write_header(av_format_ctx, NULL);
 	if (response < 0) {
 		UtilityFunctions::printerr("Error when writing header!", get_av_error());
-		return -6;
+		return -12;
 	}
 	av_packet_free(&av_packet_video);
 	i = 0; // Reset i for send_frame
-	return 0;
+	return OK;
 }
 
-// TODO: Make argument int frame_nr, this could allow for multi-threaded rendering ... maybe
 int Renderer::send_frame(Ref<Image> a_frame_image) {
 	if (!av_codec_ctx_video) {
 		UtilityFunctions::printerr("Video codec isn't open!");
@@ -323,7 +321,7 @@ int Renderer::send_frame(Ref<Image> a_frame_image) {
 	response = avcodec_send_frame(av_codec_ctx_video, av_frame_video);
 	if (response < 0) {
 		UtilityFunctions::printerr("Error sending video frame!", get_av_error());
-		return -1;
+		return -3;
 	}
 
 	av_packet_video = av_packet_alloc();
@@ -379,12 +377,12 @@ int Renderer::send_audio(Ref<AudioStreamWAV> a_wav) {
 	// i += av_frame_audio->nb_samples;
 	// while loop end to repeat
 
-	return 0;
+	return OK;
 }
 
 int Renderer::close() {
 	if (av_codec_ctx_video == nullptr)
-		return 1;
+		return -1;
 
 	av_write_trailer(av_format_ctx);
 
@@ -404,5 +402,5 @@ int Renderer::close() {
 		avio_closep(&av_format_ctx->pb);
 	avformat_free_context(av_format_ctx);
 
-	return 0;
+	return OK;
 }
diff --git a/src/video.cpp b/src/video.cpp
index 2365073..a9b838b 100644
--- a/src/video.cpp
+++ b/src/video.cpp
@@ -28,36 +28,26 @@ Dictionary Video::get_video_file_meta(String a_file_path) {
 	return l_dic;
 }
 
-// possible return values:
-// 0: OK;
-// 1: Couldn't properly open file and collect stream data;
-// 2: Codec problems;
-// 3: Sws problems;
-// 4: Variable framerate (not supported);
-// 5: Trouble loading audio;
-// 6: Invalid frame-rate;
-// 7: Not usable video file;
-//
 int Video::open_video(String a_path, bool a_load_audio) {
 	// Allocate video file context
 	av_format_ctx = avformat_alloc_context();
 	if (!av_format_ctx) {
 		UtilityFunctions::printerr("Couldn't allocate av format context!");
-		return 1;
+		return -1;
 	}
 
 	// Open file with avformat
 	if (avformat_open_input(&av_format_ctx, a_path.utf8(), NULL, NULL)) {
 		UtilityFunctions::printerr("Couldn't open video file!");
 		close_video();
-		return 1;
+		return -1;
 	}
 
 	// Find stream information
 	if (avformat_find_stream_info(av_format_ctx, NULL)) {
 		UtilityFunctions::printerr("Couldn't find stream info!");
 		close_video();
-		return 1;
+		return -1;
 	}
 
 	// Getting the audio and video stream
@@ -68,19 +58,18 @@ int Video::open_video(String a_path, bool a_load_audio) {
 			continue;
 		else if (av_codec_params->codec_type == AVMEDIA_TYPE_AUDIO) {
 			av_stream_audio = av_format_ctx->streams[i];
-			if (a_load_audio && !_get_audio())
-				return 5;
+			if (a_load_audio && !(response = _get_audio()))
+				return response;
 		} else if (av_codec_params->codec_type == AVMEDIA_TYPE_VIDEO)
 			av_stream_video = av_format_ctx->streams[i];
 	}
 
 	// Setup Decoder codec context
-	UtilityFunctions::print("Setting up video decoder ...");
 	const AVCodec *av_codec_video = avcodec_find_decoder(av_stream_video->codecpar->codec_id);
 	if (!av_codec_video) {
 		UtilityFunctions::printerr("Couldn't find any codec decoder for video!");
 		close_video();
-		return 2;
+		return -3;
 	}
 
 	// Allocate codec context for decoder
@@ -88,21 +77,21 @@ int Video::open_video(String a_path, bool a_load_audio) {
 	if (av_codec_ctx_video == NULL) {
 		UtilityFunctions::printerr("Couldn't allocate codec context for video!");
 		close_video();
-		return 2;
+		return -3;
 	}
 
 	// Copying parameters
 	if (avcodec_parameters_to_context(av_codec_ctx_video, av_stream_video->codecpar)) {
 		UtilityFunctions::printerr("Couldn't initialize video codec context!");
 		close_video();
-		return 2;
+		return -3;
 	}
 
 	// Open codec - Video
 	if (avcodec_open2(av_codec_ctx_video, av_codec_video, NULL)) {
 		UtilityFunctions::printerr("Couldn't open video codec!");
 		close_video();
-		return 2;
+		return -3;
 	}
 	
 	// Enable multi-threading for decoding - Video
@@ -126,7 +115,7 @@ int Video::open_video(String a_path, bool a_load_audio) {
 	if (!sws_ctx) {
 		UtilityFunctions::printerr("Couldn't get SWS context!");
 		close_video();
-		return 3;
+		return -4;
 	}
 
 	// Byte_array setup
@@ -142,15 +131,17 @@ int Video::open_video(String a_path, bool a_load_audio) {
 	bool l_duration_from_bitrate = av_format_ctx->duration_estimation_method == AVFMT_DURATION_FROM_BITRATE;
 	if (l_duration_from_bitrate) {
 		UtilityFunctions::printerr("This video file is not usable!");
-		return 7;
+		return -5;
 	}
 	response = av_seek_frame(av_format_ctx, -1, start_time_video, AVSEEK_FLAG_FRAME | AVSEEK_FLAG_ANY);
 	if (response < 0) {
 		print_av_error("Seeking to beginning error: ");
+		return -5;
 	}
 	_get_frame(av_codec_ctx_video, av_stream_video->index);
 	if (response) {
 		print_av_error("Something went wrong getting first frame!");
+		return -5;
 	}
 
 	// Checking for interlacing and what type of interlacing
@@ -161,7 +152,7 @@ int Video::open_video(String a_path, bool a_load_audio) {
 	framerate = av_q2d(av_guess_frame_rate(av_format_ctx, av_stream_video, av_frame));
 	if (framerate == 0) {
 		UtilityFunctions::printerr("Invalid frame-rate for video found!");
-		return 6;
+		return -6;
 	}
 
 	// Setting variables
@@ -174,8 +165,8 @@ int Video::open_video(String a_path, bool a_load_audio) {
 		if (av_stream_video->r_frame_rate.num == av_stream_video->avg_frame_rate.num) {
 			variable_framerate = false;
 		} else {
-			UtilityFunctions::print("Variable framerate detected, aborting! (not supported)");
-			return 4;
+			UtilityFunctions::printerr("Variable framerate detected, aborting! (not supported)");
+			return -6;
 		}
 	}
 
@@ -187,8 +178,8 @@ int Video::open_video(String a_path, bool a_load_audio) {
 	video_duration = av_format_ctx->duration;
 	if (av_stream_video->duration == AV_NOPTS_VALUE || l_duration_from_bitrate) {
 		if (video_duration == AV_NOPTS_VALUE || l_duration_from_bitrate) {
-			UtilityFunctions::print("Video file is not usable!");
-			return 7;
+			UtilityFunctions::printerr("Video file is not usable!");
+			return -7;
 		} else {
 			AVRational l_temp_rational = AVRational{1, AV_TIME_BASE};
 			if (l_temp_rational.num != av_stream_video->time_base.num || l_temp_rational.num != av_stream_video->time_base.num)
@@ -201,7 +192,6 @@ int Video::open_video(String a_path, bool a_load_audio) {
 	av_packet_free(&av_packet);
 	av_frame_free(&av_frame);
 
-	UtilityFunctions::print("Video is open!");
 	is_open = true;
 	return OK;
 }
@@ -231,16 +221,13 @@ void Video::print_av_error(const char *a_message) {
 	UtilityFunctions::printerr((std::string(a_message) + l_error_buffer).c_str());
 }
 
-bool Video::_get_audio() {
+int Video::_get_audio() {
 	// Audio Decoder Setup
-	UtilityFunctions::print("Setting up audio decoder ...");
-
-	// Setup Decoder codec context
 	const AVCodec *av_codec_audio = avcodec_find_decoder(av_stream_audio->codecpar->codec_id);
 	if (!av_codec_audio) {
 		UtilityFunctions::printerr("Couldn't find any codec decoder for audio!");
 		close_video();
-		return false;
+		return -2;
 	}
 
 	// Allocate codec context for decoder
@@ -248,21 +235,21 @@ bool Video::_get_audio() {
 	if (av_codec_ctx_audio == NULL) {
 		UtilityFunctions::printerr("Couldn't allocate codec context for audio!");
 		close_video();
-		return false;
+		return -2;
 	}
 
 	// Copying parameters
 	if (avcodec_parameters_to_context(av_codec_ctx_audio, av_stream_audio->codecpar)) {
 		UtilityFunctions::printerr("Couldn't initialize audio codec context!");
 		close_video();
-		return false;
+		return -2;
 	}
 
 	// Open codec - Audio
 	if (avcodec_open2(av_codec_ctx_audio, av_codec_audio, NULL)) {
 		UtilityFunctions::printerr("Couldn't open audio codec!");
 		close_video();
-		return false;
+		return -2;
 	}
 
 	// Enable multi-threading for decoding - Audio
@@ -287,29 +274,27 @@ bool Video::_get_audio() {
 	if (response < 0) {
 		print_av_error("Failed to obtain SWR context!");
 		close_video();
-		return false;
+		return -8;
 	} else if (!swr_ctx) {
 		UtilityFunctions::printerr("Could not allocate re-sampler context!");
 		close_video();
-		return false;
+		return -8;
 	}
 
 	response = swr_init(swr_ctx);
 	if (response < 0) {
 		print_av_error("Couldn't initialize SWR!");
 		close_video();
-		return false;
+		return -8;
 	}
 
-	UtilityFunctions::print("Getting audio ...");
-
 	// Set the seeker to the beginning
 	int start_time_audio = av_stream_audio->start_time != AV_NOPTS_VALUE ? av_stream_audio->start_time : 0;
 	avcodec_flush_buffers(av_codec_ctx_audio);
 	response = av_seek_frame(av_format_ctx, -1, start_time_audio, AVSEEK_FLAG_FRAME | AVSEEK_FLAG_ANY);
 	if (response < 0) {
 		UtilityFunctions::printerr("Can't seek to the beginning of audio stream!");
-		return false;
+		return -9;
 	}
 
 	av_packet = av_packet_alloc();
@@ -378,8 +363,7 @@ bool Video::_get_audio() {
 	av_frame_free(&av_frame);
 	av_packet_free(&av_packet);
 
-	UtilityFunctions::print("Audio successfully saved to memory!");
-	return true;
+	return OK;
 }
 
 Ref<Image> Video::seek_frame(int a_frame_nr) {
@@ -405,7 +389,7 @@ Ref<Image> Video::seek_frame(int a_frame_nr) {
 	while (true) {
 		_get_frame(av_codec_ctx_video, av_stream_video->index);
 		if (response) {
-			UtilityFunctions::print("Problem happened getting frame in seek_frame! ", response);
+			UtilityFunctions::printerr("Problem happened getting frame in seek_frame! ", response);
 			break;
 		}
 
diff --git a/src/video.hpp b/src/video.hpp
index 426168d..4e081d0 100644
--- a/src/video.hpp
+++ b/src/video.hpp
@@ -69,7 +69,7 @@ class Video : public Resource {
 	Ref<Image> next_frame();
 
 	inline Ref<AudioStreamWAV> get_audio() { return audio; };
-	bool _get_audio();
+	int _get_audio();
 
 	inline float get_framerate() { return framerate; }